1. Field of the Invention
The present invention relates to an inductive detection type rotary encoder for measuring a rotation angle of an object by use of magnetic flux coupling between wirings provided in a rotor and a stator.
2. Description of the Related Art
A rotary encoder includes a stator arranging therein a transmission wiring and a reception wiring, and a rotor arranging therein a magnetic flux coupler capable of magnetic flux coupling therewith (see U.S. Pat. No. 7,385,389). When the rotary encoder is applied to a hand tool such as micrometer, a plurality of tracks (transmission wiring, reception wiring and magnetic flux coupler) generating signals with different wavelengths need to be collected and the outer diameter of the rotary encoder needs to be reduced.
In an inductive detection type rotary encoder, at least two tracks are required to measure an absolute position (see U.S. Pat. No. 7,385,389, for example). However, when two tracks are concentrically arranged like the apparatus described in U.S. Pat. No. 7,385,389, the outer diameter of the inductive detection type rotary encoder increases.